$Withionmove

出自 DDCC TCAD TOOL Manual
於 2019年8月18日 (日) 21:15 由 Yrwu (對話 | 貢獻) 所做的修訂

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When the system has ion to perform as drift-diffusion equations, we solve the time dependent drift-diffusion for slow ion move simulation. Since the ion moves may not be governed fermi-level concept. We simply treat is a tradiational drift-diffusion equations.

 \frac{\partial M_{ion}}{\partial t} = \nabla \left( (q_{sign}) e\mu M_{ion} \vec{E} - q D_{M} \nabla M_{ion} \right)

Ideally, the ion density is given by initial setting. The total ion number should be fixed. The program is aim to model multi-ions drift-diffusion. The command is as following.

$Withionmove
 N_{sweep}   N_{output}
Sweep_type_1  T_{1,stop}  dt_{1} P1 P2 P3 P4 P5 ...
Sweep_type_1  T_{2,stop}  dt_{2} P1 P2 P3 P4 P5 .. 
 ... 
 ...
Sweep_type_N_{sweep  T_{N_{sweep},stop}  dT_{M_{sweep}}  P1 P2 P3 P4 P5 ..
 N_{ions} ~~ q_{sign,1} ~~ q_{sign,2} ~~ q_{sign,3}  ....~~ q_{sign,N_{ions}} 
 P_{type,1} ~~ M_{ions,1} \mu  p3 p4 Parameters of the 1 layer
 P_{type,2} ~~ M_{ions,2} \mu  p3 p4 Parameters of the 2 layer
 P_{type,3} ~~ M_{ions,3} \mu  p3 p4 Parameters of the 3 layer
 ....
 .....
 P_{type,N} ~~ M_{ions,N} \mu  p3 p4 Parameters of the $totalregion layer
 N_{sweep} : The number of runs for the time step
 N_{output}: The number of output results for each run
Sweep_type:
1: constant voltage, P1 to P5 is not used
2: Sweep Vg during this time period P1=Vgstart, P2=Vgend, P3=swdt of each step  (step Number=  T_{1,stop}/swdt
3: Sweep Vd during this time period P1=Vdstart, P2=Vdend, P3=swdt of each step 
4,5,6.... leave for future use
T_{1,stop} : The time for the first run. T_{2,stop}The time for the 2nd run. 
dt_{1} is the \delta t for each sweep. 
 N_{ions}  How many ions are considered. If we only want to consider 1 negative ion,we can put 1
 q_{sign}  The sign of ions. only accept  \pm 1.0 

For example: Consider 2 ions, 1st is negative charges, 2nd is positive charges, total 5 Regions we can

$Withionmove
3 1000
1 1.00  1.0d-4 
3 1.00  1.0d-4 0.0 1.0 0.02  
1 1.00  1.0d-4
2 -1.0 1.0
1 0.0e17 0.0      0.0e17 0.0   
1 1.0e17 1.0e-11  2.0e17 1.0e-12
1 1.0e17 1.0e-11  2.0e17 1.0e-12
1 1.0e17 1.0e-11  2.0e17 1.0e-12
1 1.0e17 1.0e-11  2.0e17 1.0e-12
P_{type,1} is the parameter type:  it depends on ion number  N_{ions}
1:  M_{ions,1} ~~~\mu ,  M_{ions,2} ~~~\mu ,........  M_{ions,N_{ions}}, ~~~\mu_{N_{ions}}
2:  M_{ions,1} ~~~\mu ~ D_{M},  M_{ions,2} ~~~\mu~~D_{M} ,........  M_{ions,N_{ions}}, ~~~\mu_{N_{ions}}~~ D_{M}

When type 1 is chosen, we only put mobility  \mu , and the diffusion coefficient  D_{M} is calculated with Einstein relation, where

  D_{M} = \mu k_{B} T / q